1. Field of the Invention
The present invention is related to transportation and more particularly to locating charging stations for electric vehicles (EVs).
2. Background Description
The typical electric vehicle (EV) operates on a large on board energy storage cell or rechargeable battery. EV battery capacity limits the distances EVs can travel on a single charge. Historically, high capacity batteries and sufficiently large, high efficiency electric motors for long range travel have been unavailable. So, EV travel distances have been relatively short. The expected remaining range for each EV depends upon the distance travelled, road topology, traffic conditions and weather conditions. Morrow et al., “Plug-in Hybrid Electric Vehicle Charging Infrastructure Review,” US DOE Report, Contract No. 58517, November 2008, notes that in the absence of commercial charging stations, the EV charge depletion range falls from 40 to 13 miles if charging stations are available outside residences. Most EV drivers have sufficient charge capacity at home for short-range, local travel. Frequently however, drivers are in a situation where vehicles must be refueled away from home, e.g. at workplace, a shopping center or an event location.
Unfortunately, current EV infrastructure has few, sparsely located commercial charging stations. Typically, charging stations are placed at locations haphazardly selected, on an ad hoc basis. However, those locations may not be suited for EV traffic and/or charging needs, where a recharge may typically take several hours. This current EV infrastructure has been, therefore, an impediment to widespread adoption of EVs. The travel distances between charging stations, where available, has suppressed EV popularity. In 2000 there were only 9,367 EV in operation in the U.S. More recently, because designers focused on developing higher capacity batteries and increasing electric motor efficiency and capacity, EV popularity has been steadily increasing. On the low end, Pike Research estimates that the yearly U.S. sales of EVs will increase to 204,110 by 2015. The Federal government has set goals to have about 1 million EVs on road by 2015. However, continuing this trend (and inherent in these estimates), requires adequate EV infrastructure with geographically distributed recharge capacity.
Thus, there is a need for EV infrastructure with commercial EV charging stations located based on demand for the service.